Frequency of Urinary Tract Infection Among Patients Undergoing Implant Fixation for Acute Trauma

Objective: This study aims to determine the frequency of urinary tract infection (UTI), identify the isolated bacteria, and assess antibiotic sensitivity in patients undergoing orthopedic implant fixation for hip fractures. Methodology: After ethical approval from the institutional review board, this retrospective cross-sectional study was conducted at the Orthopedic Surgery Department of Dow University Hospital Karachi from June 2022 to June 2023. Through non-probability consecutive sampling, 186 patients above 16 years of age, of either gender, presenting with hip fractures such as intracapsular or extracapsular fractures, who underwent surgical fixation, were included in the study. A urine sample for urinalysis of these patients was sent on admission. Patients who presented with open fractures or those treated with conservative management were excluded from the study. The fracture diagnosis was confirmed on radiographs. All other relevant baseline investigations were also performed before surgery, per protocol, and urine-detailed and cultured reports were followed. In addition, each patient was asked about common symptoms of UTI before surgery and then diagnosed with UTI on positive urine culture and sensitivity (CS). Results: Out of 186 hip fracture patients, 98 (52.7%) were males and 88 (47.3%) were females, with a mean age of 61.03 ± 16.43 (16-96) years. Pre-operative UTI symptoms were reported by 79 patients, including dysuria (16; 20.3%), polyuria (19; 24.0%), and burning (44; 55.7%). UTI was diagnosed on culture and sensitivity report in 65 (34.9%) patients with Escherichia coli as commonly diagnosed bacteria 35 (53.8%), followed by Enterococcus 8 (12.4%), Klebsiella 7 (10.9%), Pseudomonas aeruginosa 3 (4.7%), and Acinetobacter 2 (3.1%) patients. E. coli was sensitive to amikacin, amoxicillin/clavulanic acid, ampicillin, cefixime, ceftriaxone, cefuroxime, ciprofloxacin, colistin, cotrimoxazole, fosfomycin, gentamycin, levofloxacin, meropenem, nitrofurantoin, polymyxin B, and piperacillin-tazobactam. Conclusion: Urinary tract infection is common in patients undergoing orthopedic implant fixation for hip fractures, which can lead to potentially serious outcomes. Overall, hygiene, prompt treatment, and standard protocol should be utilized to treat those infected and minimize the spread.


Introduction
Surgical site infection (SSI) is a significant and detrimental consequence observed in patients with hip fractures.Studies have found a one-year mortality rate of over 50% in individuals who develop SSI, whereas those without SSI have a mortality rate of approximately 30% [1].According to the surveillance report for the 2021-2022 period by the UK Health Security Agency, it was observed that the SSI rate for total hip replacement surgery in NHS (National Health Service) hospitals in England was 0.5% for cases involving acute trauma and chronic elective indications.
In contrast, the SSI rate for surgeries involving repair of neck of femur fracture, which included hip hemiarthroplasty and fracture fixation, was 0.8%.Based on the surveillance report for the period of 2021-2022 by the UK Health Security Agency, it was seen that Enterobacterales was the predominant causative organisms for SSIs across various surgical specialties.Furthermore, there was an upward trend in their prevalence over ten years [2].Escherichia coli was identified as the predominant species within the Enterobacterales order.The occurrence of SSIs caused by Enterobacterales was found to be 18.3% for superficial infections and 20.3% for deep infections in patients who underwent hip replacement surgery.Additionally, 55% of deep polymicrobial infections following surgery to repair a fractured neck of the femur featured Gram-negative bacteria.Given that Enterobacterales are the primary etiological agents responsible for urinary tract infection (UTI), there exists a legitimate concern regarding the potential association between UTI and SSI after hip fracture surgery [3].
The understanding of the relationship between UTI's and SSIs in individuals with hip fractures is limited.At now, there exists a lack of agreement regarding the necessity of screening for and treating UTIs in individuals with hip fractures [4].Patients who experience hip fractures tend to be of advanced age and have a higher prevalence of underlying medical conditions, in comparison to individuals undergoing elective hip surgery [5].This demographic profile renders them more vulnerable to the adverse consequences associated with SSI [6].While it may be possible to postpone elective arthroplasty in cases where symptomatic bacteriuria is present, it is crucial to promptly perform surgical intervention for hip fractures.Ideally, this intervention should occur within 36 hours of the injury, as prolonged delays have been linked to increased death rates.Therefore, it is impractical to delay the assessment of urine culture results and the resolution of urinary tract infections in patients with hip fractures.Additionally, UTIs may occur following hip fracture surgery.Urinary catheterization is commonly employed in individuals with hip fractures as a means to prevent or manage urinary retention, accommodate the restricted mobility of patients, and enable the monitoring of urine flow.Urinary catheterization poses a potential risk for UTI due to the catheter's potential to serve as a site for bacterial colonization [7].However, there is currently no consensus on the correlation between urinary catheterization (whether inserted before or following the occurrence of a hip fracture) and the risk of SSI in patients with hip fractures.
A limited number of studies have indicated the need to identify UTIs in patients undergoing Orthopedic surgery to prevent surgical failure.Having said that, there is still lack of well-documented data regarding the occurrence of UTIs specifically related to Orthopedic implant fixation [8].Hence, the present study was conducted in a tertiary care facility in Karachi to ascertain the frequency of urinary tract infection (UTI), identify the isolated bacteria, and assess antibiotic sensitivity in patients undergoing Orthopedic implant fixation for hip fractures.

Materials And Methods
After ethical approval from the Institutional Review Board of Dow University of Health Sciences, this retrospective cross-sectional study was conducted at the Orthopedic Surgery Department of Dow University Hospital Karachi from June 2022 to June 2023.Through non-probability consecutive sampling 186 patients above 16 years of age, of either gender, with hip fractures, intracapsular or extracapsular, who underwent surgical fixation were included in the study.Extracapsular hip fractures included those that occur below the hip joint capsule, such as intertrochanteric and subtrochanteric fractures.Intracapsular hip fractures are those that occur at the hip joint capsule, including femoral head and femoral neck fractures.All fractures were surgically managed, with internal fixation in intracapsular fractures and arthroplasty in extracapsular fractures.
Patients refusing surgical intervention or those with open fractures were excluded from the study.Each patient was evaluated for demographic data, medical history, any comorbidities, and pre-operative symptoms of UTI such as dysuria, polyuria, and burning.Clinical examination of each patient was performed for identification of fracture.Diagnosis of fracture was confirmed based on radiological examination including X-ray and computed tomography (CT).
Each patient was informed about fracture and its surgical management (internal fixation or arthroplasty).A urine analysis of each patient was sent along with pre-operative labs.Mid-stream sample of urine was sent, and urinary catheterization of the patient was done if needed.The urine detailed report was indicated as positive if bacteria was present in sample and then diagnosis for UTI was confirmed on positive urine culture and sensitivity (CS).Collected results were interpreted with Statistical package for social sciences (SPSS) version 21.0 (IBM Inc., Armonk, NY, USA).Data presented in tables are shown as mean ± standard deviation for continuous variables, frequency and percentages for categorical variables.Stratification was done with outcome by applying chi-square test with significant p-value of ≤ 0.05.

Discussion
Infection is a common and significant complication frequently encountered by Orthopedic specialists after Orthopedic surgery, causing substantial harm and consequences.Despite advancements in medical tools, the use of pre-operative and postoperative antibiotics, and adherence to standard surgical procedures, infections remain a notable complication in Orthopedic implant fixation.These infections not only lead to implant failure but also contribute to increased morbidity and mortality rates [9,10].
Urinary tract infection (UTI) stands as the fourth leading cause of health-related infections, particularly in the context of an escalating infection risk among hospitalized patients.The reported incidence of UTIs linked to improper catheterization ranges from approximately 70% to 80%.Widely recognized as a significant risk factor for initiating and exacerbating UTIs, urinary catheterization plays a pivotal role in this scenario.UTIs, acquired within a hospital setting and caused by pathogenic bacteria, lead to the formation of bacteria reservoirs resistant to medications, culminating in elevated rates of illness and death [11,12].
Consequently, the present study aims to investigate the prevalence of UTIs among individuals undergoing Orthopedic implant fixation treatment for hip fractures.Additionally, the research endeavors to pinpoint the specific pathogenic bacteria responsible for these infections and assess their susceptibility to various antibiotics.
Within the sample size in the current study, it reveals a noteworthy incidence of urinary tract infections (UTIs) among patients undergoing Orthopedic implant fixation.In a research conducted by Koulouvaris et al. (2009), the prevalence of postoperative UTIs in patients undergoing Joint Arthroplasty was documented at 6.9% [13].Thakker et al. ( 2018) observed an initial frequency of 2.1% among Orthopedic surgery patients, which significantly decreased to 1.1% after the implementation of a quality improvement strategy [12].Additionally, Alvarez et al. ( 2016) reported a post-operative UTI rate of 1.1% in patients undergoing joint arthroplasty [14].
There is a significant disparity in the occurrence of urinary tract infections (UTIs) in recent academic studies when compared to other developed nations [15].This variation can be ascribed to differences in the use of cutting-edge medical and surgical instruments, the presence of advanced facilities in operating rooms, the availability of well-trained healthcare professionals, and strict adherence to established operating procedures and protocols.
As noted in the results, Escherichia coli is the primary isolated bacteria in majority of the patients, followed by Enterococcus, Klebsiella, Pseudomonas Aeruginosa and Acinetobacter.In Koulouvaris et al. ( 2009) led study, it was observed that among urinary tract infection (UTI) patients, 50.0% had Escherichia coli, while the remaining 50.0% had Enterococcus [13].Another Investigation by Yassa et al. (2017) focusing on preoperative UTIs found that Escherichia coli was the most frequently identified bacterium, followed by Enterococcus faecalis and Pseudomonas [16].The prevailing literature consistently emphasizes that Escherichia Coli stands out as the most identified bacterium in instances of urinary tract infections [17].
Our study highlights a significant link between urinary tract infections (UTIs) and gender, revealing a statistically significant correlation, with prevalence of UTIs notably higher in female patients.Koulouvaris et al. (2009) reported a distribution of 65.5% female patients and 34.5% male patients diagnosed with UTIs [13].Numerous addition studies consistently establish that being female is a substantial risk factor for UTIs, with females experiencing a rate four times higher than males [14,18].
We also demonstrated association between UTIs and various factors, including gender diabetes mellitus and urinary catheterization.A considerable percentage of female patients, diabetic patients, and those with urinary catheters were found to be affected by UTIs.[12].Several studies consistently identify characteristics such as female gender, diabetes mellitus, and urinary catheterization as significant risk factors for UTIs, with the incidence in females being four times higher than in males [14][15][16][17][18].
In the context of Orthopedic implant fixation, urinary catheterization poses a substantial risk for UTIs, especially in underdeveloped nations.Varied procedures for urine catheterization are employed in different Orthopedic settings due to the absence of widely accepted standardized criteria.Although routine catheterization is often recommended in Orthopedic settings to reduce postoperative urinary retention, a significant risk factor for UTIs in patients undergoing Orthopedic implant fixation [9,12,13], limited research has been conducted on reducing UTI prevalence by minimizing the use of urinary catheterization [14].
The approach to managing urinary tract infections (UTIs) in individuals with hip fractures may differ depending on the particular clinical context and the patient's general health condition.The existence of a universally applicable procedure for screening and treating urinary tract infections (UTIs) in hip fracture patients is lacking, as the appropriate method is contingent upon various aspects such as the patient's symptoms, medical history, and the guidelines established by the healthcare facility.Nevertheless, healthcare providers adhere to broad rules and principles while managing urinary tract infections (UTIs) in this specific demographic.
Clinical Assessment performed by healthcare workers evaluates patients for urinary tract infection symptoms.These symptoms may include increased urination frequency, urgency, burning, lower abdominal discomfort, and murky or malodorous urine.UTI symptoms may appear unnoticeable in the elderly, such as cognitive impairment, weariness, or worsening of pre-existing medical conditions.
Urinalysis, a frequent diagnostic test, detects bacteria, white blood cells, and other infection signs in urine.
Positive urinalysis results and symptoms can support a urinary tract infection diagnosis.Sometimes a urine culture is ordered to identify the bacterial species causing the infection and choose the best treatment.However, urgent intervention is sometimes necessary, making the above step unnecessary.When a UTI is suspected and symptoms occur, healthcare providers usually start antibiotic therapy immediately.Antibiotics are chosen based on the patient's allergy history, prior antibiotic use, and local antibiotic resistance.
Hospitals and healthcare facilities adopt measures to reduce urinary tract infections.These measures usually include strict hygiene, catheter management, and timely movement, which reduce hip fracture patients' UTI risk.Recognizing that conditions vary, healthcare professionals use their clinical skills to choose the best course of action.Medical studies and standards evolve constantly.Thus, data and studies may change methods and practices over time.
Data obtained in this study is retrospective, so a limitation noted was that patients were not followed up after positive cultures and we lacked to determine if the subsequent cultures showed any growth after antibiotic therapy.A follow-up of patients would have also been beneficial to determine correlation between positive urinary cultures and presence of surgical site infection.Given the limited sample size, a large scale and multi center study would be beneficial in identifying more strains of urinary bacteria in hip fractures.

Conclusions
Urinary tract infection is common in patients undergoing Orthopedic implant fixation for hip fractures.
Major risks are involved if intervention is not undertaken.Healthcare providers should choose treatment plan according to patients' culture and sensitivity report.While managing urinary tract infections, healthcare facilities should set standard guidelines and take strict precautions to prevent spread of bacteria.

TABLE 1 : Demographic and Clinical Parameters of Study Participants
*Mean± S. D. (Standard Deviation)Site of fracture was right in 115 (61.8%) patients and left in 71 (38.2%) patients (Table2).Location of the fracture was intracapsular in 69 (37.1%) patients and extracapsular in 117 (62.9%) patients, and same values are indicated with the operative procedure performed for each type of fracture, respectively.Fracture was displaced in 126 (67.7%) patients and non-displaced in 60 (32.3%) patients.

TABLE 4 : UTI Diagnostic Test
Data was stratified according to patients' age, gender, and comorbidities.(Table5).A significant difference (p=0.002) was observed in the occurrence of UTI in females, while a significant difference (p=0.028) was observed with the occurrence of UTI in patient aged above 45 years.The occurrence of UTI was higher in the patients having diabetes (p=0.003).

TABLE 6 : Antibiotic Sensitivity of Isolated Bacteria
In Koulouvaris et al.'s (2009) study, 65.5% of the patients were female, and 6.9% had urinary catheters, both groups experiencing UTIs [13].Alvarez et al. (2016) observed that 72.2% of patients were female, 19.8% had diabetes, and all of them were diagnosed with UTIs [14].Thakker et al. (2018) reported an initial urine catheterization rate of 55.2% among Orthopedic surgery patients, which decreased to 19.8% after applying quality improvement efforts, such as catheter use guidelines and education of front line staff on catheter precautions